1. Field of the Invention
The present invention relates to waste bioremediation. More particularly, the present invention relates to compositions and methods for the bioremediation of hydrocarbon-containing waste, such as drill mud and drill cuttings from oil and gas wellbores, drill waste deposit sites, oil spills, and contaminated surfaces.
2. Description of the Related Art
Drilling wells to recover of oil and gas is typically accomplished by using a rig to drill the well with a hollow drill string. As the well is being drilled, drilling mud is pumped down the bore of the string. The drilling mud is used to control subsurface pressures, lubricate the drill bit, stabilize the well bore, and carry to the surface the cuttings produced by the drill bit by grinding rocks into small pieces. The solids are separated from the mud to return the mud to the recirculating mud system and make the solids easier to handle. The cuttings separated from the mud at shale shakers or other mechanical processors are often coated with so much mud that they are unsuitable for the next reuse or disposal step or are difficult or handle or transport. The constituents of the cuttings or the mud coating of the cuttings may leach from the waste, making them unsuitable for land application or burial approaches.
Traditional waste management methods include solidifying and stabilizing the cuttings and the mud coating using additives. Typically, cement, fly ash, lime, saw dust, and calcium oxide are used as solidification/stabilization additives for bioremediating drill cuttings and other types of wet solids. Other additives include medium-ground mica-based material, fine-ground mica, mixtures of recycled cellulose fibers, walnut nut plug, and pecan nut plug. However, not all drilling wastes are amenable to chemical fixation and stabilization treatments. Many additives either do not achieve the desired goals once the solidified or stabilized wastes are placed into the environment or the cost of using the additives is prohibitive. Most of the traditional solidification/stabilization systems produce conditions both of high pH and high total alkalinity. Much concern has been expressed about the long-term stability of such processes. Of greatest concern is the failure of the additives to keep the waste constituents from releasing into the environment over the long term or the sudden release of contaminants due to breakdown of the matrix.
Similar waste management problems also exist with oil spills, including releases of crude oil from tankers, offshore platforms, drilling rigs and wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products, and heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil. Spills may take months or even years to clean up. Dispersants are often used in an attempt to clean oil spills. Dispersants act as detergents, clustering around oil globules and allowing the oil to be carried away in the water. Smaller oil droplets, scattered by currents, may cause less harm and may degrade more easily. But the dispersed oil droplets infiltrate into deeper water and can lethally contaminate coral and break the balance of the aquatic system, affect environmental safety and damage the health of all life forms in the food chain. Oil spills also occur in the ground where pipelines are located. There is also the problem of landfills used to store oil-related wastes.
Therefore, there is a need for an effective and cost efficient system and methods for eliminating pollutants from a wide range of sources.